Sustainable Surfactant-Assisted Lignocellulosic Packaging Foams: Humidity-Responsive Shape Memory and Dusting Reduction

Low-density lignocellulosic foams offer a sustainable alternative to conventional packaging materials; however, their low density increases shipping costs, and dust generation during handling can limit their practical use. In this study, we demonstrate that these foams can be compressed into thin sheets to reduce shipping volume and subsequently recover up to 65% of their original thickness when exposed to 85% relative humidity (RH). The recovered foams retained favorable thermal insulation properties suitable for packaging applications. We further show that surface coating with cellulose nanofibrils (CNFs) significantly reduces dust generation during handling while improving compressive strength compared to uncoated foams. Incorporation of alkyl ketene dimer (AKD) into the coating formulation further imparted hydrophobicity to the foam surface. Overall, the combination of compressibility, humidity-triggered shape recovery, improved mechanical performance, reduced dust generation, and enhanced surface hydrophobicity highlights the potential of CNF-coated low-density lignocellulosic foams as sustainable packaging materials with improved handling characteristics and transportation efficiency.